spring boot - How to intercept a request when using SpringBoot WebClient

Question

I am trying to use the WebClient to call my restServices. Previously on RestTemplate, we had ClientHttpRequestInterceptor defined and attached to the RestTemplate to intercept and modify the requests. With the WebClient, is there a way to do the same ?

Thanks,

-Sreeni

Answer 1

When you are using the WebClient Builder you can pass in implementations of the ExchangeFilterFunction interface using the filter() method. This is the equivalent of the ClientHttpRequestInterceptor for `RestTemplate.

WebClient Builder Docs: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/reactive/function/client/WebClient.Builder.html#filter-org.springframework.web.reactive.function.client.ExchangeFilterFunction-

ExchangeFilterFunction Docs: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/reactive/function/client/ExchangeFilterFunction.html

For example:

WebClient webClient = WebClient.builder()
        .baseUrl("http://localhost:8080|)
        .filter(logFilter())
        .build();


private ExchangeFilterFunction logFilter() {
    return (clientRequest, next) -> {
        logger.info("External Request to {}", clientRequest.url());
        return next.exchange(clientRequest);
    };
}